Kepler-1788 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1788 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1788, located approximately 1827.9 light-years (560.45 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.096% across the stellar disk), this world measures 2.379 Earth radii and has a measured mass of 6.25 Earth masses. Combining its mass and radius yields a mean bulk density of 2.56 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.1 km/s.
In its orbital architecture around Kepler-1788, Kepler-1788 b completes one full revolution every 2.8 Earth days at a semi-major axis of 0.0343 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 133.3 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 956 K (+683°C / +1261°F) and receiving 197.81 S⊕ (~269,219 W/m²), Kepler-1788 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1788 is classified as a stellar host with an effective photospheric temperature of 4,786 K, a radius of 0.704 R☉, a mass of 0.686 M☉, an estimated bolometric luminosity of 0.233 L☉. Stellar evolution modeling indicates an estimated stellar age of 13.8 Gyr and a metallicity of [Fe/H] = -0.2 dex (metal-poor relative to the Sun). From Earth, Kepler-1788 shines at apparent V-band magnitude 15.484 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-1788 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,786 K |
| Stellar Radius | 0.7040 R☉ |
| Stellar Mass | 0.6860 M☉ |
| Bolometric Luminosity | 0.233 L☉ |
| Metallicity [Fe/H] | -0.200 dex |
| Stellar Age | 13.800 Gyr |
| Apparent Magnitude | V: 15.484 · G: 15.254 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.034300 AU |
| Orbital Period | 2.8 days |
| Mean Orbital Velocity | 133.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.5400° |
| Mean Bulk Density | 2.56 g/cm³ (18.1 km/s vesc) |
| Insolation Flux | 197.8100 S⊕ (~269,219 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1827.900 LY (560.445 pc) |